An organic LED element has an organic layer. The organic LED element includes a bottom emission type which extracts light emitted by the organic layer from a transparent substrate.
The current situation of the organic LED element is that the amount of the light which can be extracted to the outside the organic LED element is less than 20% of the emitted light.
There is a document which describes that a light scattering layer comprising a glass is provided in the organic LED element to improve the light-extraction efficiency (Patent Document 1).
In recent years, environmental pollution becomes a serious problem in the melting of a glass containing lead oxide. Therefore, the glass is required to be free from lead oxide.